<template>
  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
    <el-form class="form" label-width="120px">

      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title"  placeholder="请输入课程名称"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <!-- 所属分类：级联下拉列表 -->

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <!--一级分类-->
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">

          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>

        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="(subjectChildren,index) in subjectTwoList"
            :key="index"
            :label="subjectChildren.title"
            :value="subjectChildren.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 TODO -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="(teacher,index) in teacherList"
            :key="index"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>
      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
         <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面-->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduservice/teacher/uploadPic'"
          class="avatar-uploader">
          <img style="width: 300px;height: 200px" :src="courseInfo.cover">
        </el-upload>

      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/>
        元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" style="margin-left: 735px" @click="saveOrUpdate">保存并下一步
        </el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
   import Tinymce from '@/components/Tinymce' //引入组件

  export default {
    components: { Tinymce },
    data() {
      return {
        saveBtnDisabled: false,
        courseInfo: {
          title: '',
          subjectId: '',//二级分类id
          subjectParentId: '',//一级分类id
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: '/static/1.jpg',
          price: 0
        },
        courseId:'',
        subjectOneList: [],//一级分类列表
        subjectTwoList: [],//二级分类列表
        teacherList: [],
        BASE_API: process.env.BASE_API // 接口API地址
      }
    },

    methods: {
      //上传封面成功调用的方法
      handleAvatarSuccess(res, file) {
        this.courseInfo.cover = res.data.url
      },
      //上传之前调用的方法
      beforeAvatarUpload(file) {
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2

        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      },
      //二级分类
      subjectLevelOneChanged(value) {
        //value就是一级分类id值
        for (var i = 0; i < this.subjectOneList.length; i++) {
          var oneSubject = this.subjectOneList[i]
          if (oneSubject.id == value) {
            this.subjectTwoList = oneSubject.children
            //把二级分类id值清空
            this.courseInfo.subjectId = ''

          }
        }
      },
      //查询所有的一级分类
      findAllSubjectOneList() {
        this.getRequest('/eduservice/subject/').then(res => {
          if (res) {
            this.subjectOneList = res.data.data
          }
        })
      },
      findAllTeacher() {
        this.getRequest('/eduservice/teacher/').then(res => {
          if (res) {
            this.teacherList = res.data.data
          }
        })
      },
      saveOrUpdate() {
        //判断添加还是修改
        if(!this.courseInfo.id) {
          //添加
          this.addCourse()
        } else {
          this.updateCourse()
        }
      },
      updateCourse(){
        if (this.courseInfo.title == '' ||
          this.courseInfo.subjectId == '' ||
          this.courseInfo.subjectParentId == '' ||
          this.courseInfo.teacherId == '' ||
          this.courseInfo.description == ''
        ) {
          //提示信息
          this.$message({
            type: 'warning',
            message: '请输入完整信息'
          })
        } else {
          this.putRequest('/eduservice/course/', this.courseInfo).then(res => {
            if (res) {
              //提示信息
              this.$message({
                type: 'success',
                message: res.message
              })
              //跳转到第二步
              this.$router.push({path:'/course/chapter/'+this.courseId})
            }
          })
        }
      },
      //回显
      findByCourseInfo(){
        this.getRequest("/eduservice/course/findCourseByCourseId/"+this.courseId).then(res=>{
          this.courseInfo=res.data.data
          //1 查询所有的分类，包含一级和二级
          this.getRequest('/eduservice/subject/').then(res => {
            if (res) {
              //2 获取所有一级分类
              this.subjectOneList = res.data.data
              //3 把所有的一级分类数组进行遍历，
              for(var i=0;i<this.subjectOneList.length;i++) {
                //获取每个一级分类
                var oneSubject = this.subjectOneList[i]
                //比较当前courseInfo里面一级分类id和所有的一级分类id
                if(this.courseInfo.subjectParentId == oneSubject.id) {
                  //获取一级分类所有的二级分类
                  this.subjectTwoList = oneSubject.children
                  this.findAllTeacher()
                }
              }
            }
          })
        })
      },
      addCourse() {
        if (this.courseInfo.title == '' ||
            this.courseInfo.subjectId == '' ||
            this.courseInfo.subjectParentId == '' ||
            this.courseInfo.teacherId == '' ||
            this.courseInfo.description == ''
        ) {
          //提示信息
          this.$message({
            type: 'warning',
            message: '请输入完整信息'
          })
        } else {
          this.postRequest('/eduservice/course/', this.courseInfo).then(res => {
            if (res) {
              //提示信息
              this.$message({
                type: 'success',
                message: res.message
              })
             this.$router.push({ path: '/course/chapter/' + res.data.id })
            }
          })
        }
      }
    },
    watch: {  //监听
      $route(to, from) { //路由变化方式，路由发生变化，方法就会执行
        //清空表单
        this.courseInfo = {}
        this.courseInfo.description=null
        this.courseInfo.cover= '/static/1.jpg'
        this.courseInfo.lessonNum=0
        this.courseInfo.price=0
      }
    },
    mounted() {
      //获取路由的id值
      if (this.$route.params && this.$route.params.id) {
        this.courseId = this.$route.params.id
        //回显课程信息
        this.findByCourseInfo()
      }else{
        this.findAllTeacher()
        this.findAllSubjectOneList()
      }
    }
  }
</script>

<style scoped>
  .form {
    width: 1000px;
    padding: 30px 20px 30px 0px;
    padding-right: 20px;
    margin: 10px auto;
    border: 1px solid #eaeaea;
    box-shadow: 0 0 25px #cac6c6;
  }
  .tinymce-container {
    line-height: 29px;
  }
</style>
